Clutch operating device for motor vehicles



Oct. 28,1941. u C. BTTNER 1 2,260,280

A:,LU'NH OPERATING @Ev-ICE Foa MOTOR VEHICLES l Filled Aug. :50,1958

CARL. y B rra/R k member to directly actuate thel clutch will ordi- Patented Oct. 28,l 1941 Carl Bttner, Friedrichshafen, Germany, assigner to Maybach-Motorenbau G.

drichshafen, Germany m. b. Hz; Fri

Appucationgusi 3o, 193s, serial' 110.227,553 In Germany September 1, 1937 9 Claims.

This invention relates 4to a device for engaging and disengaging clutchessuch as used in motor vehicles involving a dual arrangement which provides for manipulation of the clutch by the driver and also through servo power mechanism under `5 control of the driver.

An important object of the invention is to provide a dual operating device of the character described in which the driver 'operating means); f, which usually will comprise a foot pedal serving 'to directly actuate the clutch; also controls operate the clutch no difficulty will be experienced in actuating the clutch directly or through the power mechanism at will. Where, however, a single driver operating member, a pedal, is used a problem arises' in that actuation of the operating narily affect the servo motor control so as to causethe motor to act on the clutch at times when the driver desires to manipulate the clutch at a fast or slow rate, or in interrupted stages,

in accordance with existing conditions.

In cases where no lserv mechanism is provided and the clutch is actuated directly by the driver by a control member such as` a foot pedal through mechanical linkage, it is possible for the driver at all times to regulate the pressure on the clutch and control the'A rate of engagement or/'35 disengagement of the clutch in accordance with the resistance of the vehicle Vto` movement, the vehicle speed, etc. Ordinarily the clutch can be released rapidly without ,undesirable effects, but

i the ability to control actuation of the clutchin 40 accordance with varying conditions 'is extreme- 4ly desirable duringreengagement in order to avoid injury to the clutchand the vehicle motor as Well as to avoid annoying jerks.

While the use of servo motor devices for ac- 45 cordance with the judgment of the driver so las "m to momentarily interrupt, slow down, -or speed up the traverse of one clutch part between its position of engagement and position of complete dis-A. engagement. While hitherto a servo motor device coun ,be initiany adjusted to actuate the "5 (ci, 19a-91) clutchrapidly or slowly, the speed of movement would be the same at all times 1and was not subject to variation. Also, once the motor mechanism under initiation of the driver began to op- .erate it would move theclutch through its complete traverse 4between disengaged and engaged positions, andv if the driver attempted to interrupt operation in the motor momentarily during traverse from disengaged to engaged clutch lpositions the motor would .reverse itself so as to cause the clutch to again become completely disengaged.I

It will be obvious for the reasons indicated that while the employment of an auxiliary power device for actuating the clutch dispensed with the necessity of the driver exerting any substantial pressure the' manipulation of the clutch cannot be controlled and varied as where the clutch is directly manipulated by the driver. The employment of a common control pedal which serves to directly actuate the clutch as Well as control operation of a servo motor device of itself does not solve the difllculty or enable the driver to achieve a soft engagement of the/ clutch inv accordance with the feel of the clutch.

The device of the present invention involves a direct acting mechanical arrangement and a servo motor operator for the clutch, both manipuclutch parts eiected through the direct acting f vmechanism subject to manipulation by the drive in accordance with his judgment. l

In the combination arrangement of the invention lost motion mechanism is employed vwht-:re necessary to enable the clutch to be -manually manipulated regardless o1' the operative position of the servo motor, and to prevent' undesired r' actuation of the servo motor control during direct actuation of the clutch by the driver. As afurther-feature of the invention special mechanism is employed between the common actuating pedal and the servo motor control whereby initial movel ment of the pedal `from any starting position serves to actuate the control while permittingfurther movement of the pedal independentlyof i y the control, and whereby upon reversing the dl-l rection of movement of the pedal the motor control is immediately reversely actuated. `It is p'o'sl" sible through the inventive arrangement to effect engagement and disengagement of the clutch solely through the servo `motor mechanism, f It is. also possible to interrupt operation` of the vservo motor mechanism at an intermediate stage by temporarily bringing' the direct actuating mechanism intooperation and then later allowing the*servomotor'mechanism'to complete the `engagement of the clutch. -Sti1l further, --it is 'l -possibledafter interrupting operation 'of the servo motor at an intermediate stage to control further manipulation of the clutch towards itsengaged;y f positionV through the direct acting mechanism under the pressure, continuously or intermittent-3 'ly diminishing, exerted by the driver.

In the drawing'is shown more or less diagrammatically one embodimentI of a clutch operating f I device embodying the principle' of the invention;

certain ofthe main operating parts being shown inlongitudinal section. y lThe Qcommon driver actuatedcontrol member ,will preferably comprise the foot pedal I which is pivotally mounted for swinging movement in the vided with, a pair of spaced stops 4,0 and 4| adaptedto limit movement ofthe rod. Inchamber 31 in the ,left'portion of housing 3D through which rod 39 extendsis a spring 29 which yieldingly holds rod 39 in its left end vposition as determined by stop 4i. K an axial bore 42 in communication with chamber 3l through a 'cross bore 43 and, communicating `with the atmosphere through port 38. When rod 39 is in its -left position as shown small chamber 35 to the left of valve 32 is ventedto the atmosphere, and when rod 39 moves to the right-the usual manner. -'Aclutch actuating lever 2 is mounted-rigidly with pedal I. The clutch isv in-j dicated as comprising part 3 formed in the motor ,y

fly wheel andA part 4 on shaft 5 which in its forwardvposition engages-part 3 and is movable reari .-wardly out of!l engagement therewith against the riorceexe'rted bythe clutch spring 9. A collar on shaft 5 providedwith flanges 6 and] is engaged f by an arm 8, the latter being pivotally supported for swinging movement at its upper end. Link in is pivotally connected at its left end through pin Il to the lower end of arm 8 and its right end through'pin .12" to the clutch actuating. armA 2. Movement of vpedal from its full line towards-A its dotted line position swings arm 2 to the right andsuch movement is transmitted through link Ill and arm 8 to disengage the clutch directly v under the actuation of the pedal.

The power mechanism for actuating the clutch may be` of any known type, iiuid pressure 'or vacuum operated, etc., and a control therefore will be 'provided responsive to movement of the -pedal member l. In the embodiment shown a vacuum type servo device is employed as the power means for disengaging the clutch, the same comprising-` a 'ylinderv 20 having an operating piston 2l. The piston rod 22 of the motor may be caused to act, on, lever 2 which as abovel explained is actuatable by pedal l. To this end piston rod 22 is pivotally connected with a shortarm 24 having a longitudinal slot 23. providing a 10st motion connection with pin 25 on lever 2. VThe provision of such lost motion device enables lever 2 to be swung rearwardly to disengage the clutch independently of the servo motor.

/The servo motor is supplied with vacuum from a source AI3 which can conveniently comprise the intake manifold of the ,vehicle motor.` Vacuum supplyline |4.,has a'branch `l5 leading to chamber |i8of.a fluid actuated valve device 60, a control v"valve" 10 is. held against its seat 69 by a spring 1i, and when open such valve establishes communication between `chamber 68 and 'chamber 66, which .latter chamber connects with the. `chamber 26of the servo'motor through line 6?. i When a vacuum is created in chamber'26 of the motor piston 2| moves to the right, thus swinging lever 2 to theright and causing the clutch.' to

.be `disengaged through the operating linkage heretofore described. t j

The supplyA of vacuum to` the servo lmotor 1s Acontrolled-ffthrough pedal .l through special control mechanism, including valve 10 which has alreadyv been referred to. The control mechanism Ato its leftl end end ofy bore 42' is sealed by' engagement with valve 32 sothat upon opening of valve 32 through further traverse of rod 39 to the rightl a vacuum is established in chamber 35.

l Rod 39V is actuatedy in response to movemen of pedali, in the'present caseythroughk'special mechanism connecting with lever 2 with which the servo motor. 2l)y alsof connects. Rody 39 is f `pivotally connected to rod 44 which at its left end y is received 4in a hollow rod 45 having an arm 4B,

connected with pin 50 on arm 2 through a short slot 49l which provides for lost motion perhiittingv a certain degree of movement? of arm '2 independently-'of arm 48. H

By reason of the limited degree of movement of f rod 39 permitted by stops 40 and 4l it is' evident thatarm 2 must be capableof a substantially i greater traverse than rod 39.v Still it is important according to the invention that initial-movement of pedal i in either direction should be capable,y of immediately moving rod ,39 in one or the otherA directions to open or close valve 32. y A frictional connection is therefore provided which enables arm 32, immediately upon takeup ofthe lost motion provided'by slot'49, to actuate -rod `39 to the limits determined by stops filly and 4i and thereafter to moye to a new position as lever 2 is further moved.A 'Ihe frictional connection is pro-l vided by bushing 46 at the right end of hollow rod 45, which bushing frictionally engages rod 44. f

Bushing 46 has a suiiiciently high coemcient of friction to cause movement of rod 44 against spring ,zwhich acts on the right hand stop 4I of rod 39." V.Assumingnthat lever-2l through the frictional connection has caused movement of rod 39y to the rightand stopl 40 engages valve housing 39, rod 44 during further traverse of lever j 2 to the right will slidein bushing 46-through bore 41 ofhollow-rod 45. When lever 2 thereafter moves to the leftk spring 29 will urge rod 39 valve 32..

The 'vacuum entering chamber 3l of valve housing 30 through'line, I6 is transmitted, when valve 32 is opened through the mechanism just explained, through chamber 35 and line 36 to the right Vhand chamber 6I of valve housingf in f which chamber is a piston 63 yielding1y `held in its righthand position by spring T2 and subject to atmospheric pressure at its right end through port 62. When a vacuum condition is created inV chamber 6I piston63 moves to the left, and acts .through rod '64 to open valve 10, thus ,allowing I vacuum to be supplied through lines I4 and i5,

i chambers sa :and Baena une s1 to chamber 2e of the servo motor 20. The motor thereupon moves lever 2 to the right and vdisengages the clutch.

Rod 39 is provided with' t i position to eiect closing ,of y

When the pedal is reversely moved from its'depressed position and rod 39 is moved to the left,

valve 32 closes and piston chamber 6I in housing 60 is vented to the atmosphere through line 36, chamber 35, bores 42 and 43, chamber 31 and port 38. Piston 64l under the action ofy spring 12 vmoves to its right end. position, causing valve 'I0 to be closed by spring 1I. Chamber 26 of the servo motor will thereupon be vented to the atmosphere. This can be accomplishedl either v merelythrough leakage of air into chamber 26 through port 80 and around piston 2 I, or through the provision of a venting arrangement such as.

bores 42 and 43 which vent chamber 6I of piston 63. Clutch spring 9 will thereupon cause the clutch parts to engage.

While the detailed operation of the various l parts have been individually described the correlative operation of the diilerent parts may be more fullyunderstood by reference to what occurs in diierent positions of pedal I. Referring to the drawing a series of lines are superposed on.

A ing position of clutch arm 8 is indicated by R1.

T indicates the position to which pedal` I is moved without any movement of the clutch parts due` to lost motion existing in `lthe linkage con. necting the pedal to vthe movable clutch/ part 4,

and T1 represents the corresponding position of clutch arm 8. In moving .from position T to position S pedal I through lever 2, link I0 and arm 8 begins to move clutch part 4 tothe right and the clutch begins to slip slightly. By the timev the pedal has been moved to position S- slippage no longer occurs and the clutch hasbecome fully disengaged. pedal from position S to its fully depressed position A provides a safety factor to. insure com-` A clutch. When the driver moves clutch pedal I from rest position R, and it is assumed for the moment that the servo motor mechanism is not present, rst the lost motionbetween parts 2, I9, 8 and the clutch is taken up as thepedal moves -to position T. In moving from position T toS' pedal I causes a decrease in the pressure between clutch halves.3 and 4, and compression of clutch Further `movement oi the Still disregarding thepresence of the servo motor device, and assuming -that the clutch is to' be reengaged, movement of pedal I from A back to S" brings clutch part 4' to a position where it is just iree of clutch'part- 3. vDuring movement from S to SA as foot pressure on the pedal is gradually `decreased the clutch parts gradually engage and slip relative to .eachother to a diminishing extent, and when the pedal reaches position S the clutch parts slip only slightly.

The range between S and S is the critical part of the traverseof pedal I. By releasing the foot pressure more slowly 4on the pedal, or moving the ,pedal through'this'range intermittently, and/oi] by momentarily moving the pedal a short distance reverselyfback to the left the driver is able lto control the engagement of the clutch in accordance with the vehiclev and motor speeds so as to prevent grabbing and insure soft engagement. When thepedal is released slightly past S the clutch becomes completely engaged, and in moving on to T and nally` to its rest position R the pedal no longer aiiects the clutch.

Considering now the servo motor device and its control means in producing operation oi' the I clutch, We will again assume that pedal I is in spring 9. By the time the pedal hasreached the position S the pressure has been reduced-Sulliciently that the torque transmitted by the clutch is justinsuicient to cause positive engagement between the clutch parts, and such parts begin to slip a little relative toeach other. During movement of the pedal from S' to S" the clutch pressure gradually diminishes further with an increasing degree. of slippage between the clutch position R with thesclutch fully` engaged. In moving from R to T lever I rst traverses the distance B until pin 5|! reachesthe right end of lost motion slot 49, and then by reason of rthe frictional bushing y46 during further movement of the pedal towards T parts 49, 44 and 39 will 'move as a unit until the right end of rod 39 has traversed distance C. By the time the pedal reaches position T the end of rod 39 just engages As the pedal moves from T towards S' rod 39 moves further vto the right toppen valve 32. When stop engages the end of valve housing 30 rodf39 will move no'further androd 44 will Aslip relative to rod 45 as the pedal moves lever 2 further to the right. During all cthis time itwill be evident that the servo motor is inoperative, lever 2 being permitted to move relative to piston rod 22 by reason of the lost motion slot 23 in arm 24. l

As soon as valve 32 opens'during traverse of the pedal to S vacuum from line. I6 acts on'piston 63 in chamber 6I., and such piston moves to the left to openvalve 10. Vacuum from line I5 is then supplied throughline 61 to the servo motor, and piston .2l thereof begins to move to the right. Since movement of the pedal towards position in slot 2.3 incident to the initiation of the` control mechanism which resulted in vacuum being supplied to the servo motor, piston 2l must iirst move through a short lost motion distance y to again bring the leftend of slot 23'into engagement with pin 25 on lever 2. It is, assumed that ,this has occurred and that piston 2i has begun to move lever 2 lunder force of the vacuum slightsition where they'begin to slip by the time the pedal reaches position Si. As the piston continues t'o move the right the clutch parts will be brought to their fully disengaged position corresponding to position S" of the pedal. .since continued movement of lever 2 to the right will continue to maintain valves 32 and I0 open and continue the supply of vacuum to the servo moj `sition when lever I reaches the position S". 'Ihe pedal may be moved on by the driverto `its left end position A. n

gaged, thearrangementfissuch that th'e foot pedal may be manipulated to control and vary the clutch pressure without interferencefrom the 'servo :motor mechanism. During'the period of complete disengagement piston 2|` is in its right end position Iand lever 2 withpin 25 are in posi- 1i-,ion corresponding to position A of the pedal. j

During the reverse. movement of lever 2 towards `the left again.rods 45 and 44 being in frictional 'connection through bushing 46 and under .the

pressure of spring.29 'will move rod 39,.to the left imtil stop 4l assumes the position shown in the drawing. Therclosing of valve 32 and the venting or piston chamber 6i through bores 42 and 43 and rod\39, and lport 38 causes piston 63 to move to the right. Valve 'l0 closes to. discontinue the supply of vacuum to the `servo motor. 'As air leaks into-chamber 26 of the motor, lever V2 is moved to 1 capable.` The clutch operating lever is still capable of movement from VS1?r to A1. This correj 1 `sponds to the movement of the yfoot pedal from `S- to A.

ment offthe clutchis initiated by movement of the clutch vpedal from S" toward A, in which range the` clutchpedal; is free to move back toward S", and thereby to close valve 32:

The movement of the clutch pedal beyond the lix'nitto which it is moved by the servo motor and back again may'be carried out under. the momentumy thel clutch pedalv has received by the acthe clutch. i f l,

The rapid reengagementvof the 4clutch as the clutch motor' piston moves to the left can be interrupted and modied through manipulationof again supplied to the servo motor which would reversely move thel parts back to their completely disengaged position, by reason of the provision of valve 32.

made relatively long and stop 4| isso positioned which represents the lost motion between lever 2 andA valve 32 constitute as large as possible a part of the slippage range of the clutch representedby the distance between positions S' yand S" of the gpedal." IL-therefore, when the servo motor is venting and the clutch parts are moving towards 'Sf and 'S' the foot of the driver be-causd to hold `the pedal stationary for depressjthesame slightly,

, y' lsuch action -will be eifectiveupon lever 2 and the 1 Imechanical connecting linkage'to' stop further H movement of the clutch parts towards complete engagement, ro1.- rnove them back towards a posithe return of the clutch tovengagement ing through the mechanical connections so that l Assuming now that the clutch isto be reen- It will be` understood that the 'reverse movethe foot pedal, without causing vacuum to belost .motion in the parts 'between lever 2 andA I' between the driver,` actuated 'means and the con- According to the invention lslot 49 in arm 48is.A

engagement-with pedal l in a position betweenv mly be directly controlled by vfoot pressure acti7;

2,260,289 i 'i l tor, causing piston2l to reach` its right end-po-'f soft engagement of the clutch can be lassured since within the dlmensionsas represented by the 1 distancesB and C the pedal can be manipulatedl without effecting vthe control of the servo motor.

Itv will be understood, however, that it is not necmotor for the driver tojcontrol 'the foot pedal since the clutch spring and servo motor asI itv vents will of themselves assure the yclutch parts i -being brought back to a position of complete `engagement.

The embodiment of thekinve-nti'on as shown in l the drawing is vmerelyto be taken as illustrative,

vand the invention is/ not to be limited further than required by the scope ofthe appended claims.

Iclairn: v l l Y 1. A clutch operating device comprising a servo motor for disengaging the clutch`r and control means therefor, an operating pedal positively operatively connected directly'to the clutch kso as to y be simultaneously movable with the clutch at all u times, said pedal also being operatively connected.

to the motor control means, and 'means for effecting movement of the iootpedal relative to Aand independently of the motor control means to prof l l vide for manipulation of thel clutch independently i i of the servo motor by the foot pedal.

` ymeans therefor, direct mechanical means for optorcontrol means andsaid mechanical means,D and lost motion means operative during a part ofthe complete movement of the clutch from disengagement to engagement for preventing actuation of the motor means-.and Ymotor control means by the pedal and providing for manipulation ofthe yclutch by the pedal through the mechanical means.

3; A vehicle clutch operatingA device comprising a clutchy actuating lever, driver 'actuated 'means fonmanually operating said lever 'and being simultaneously movable at all times with. said clutch lever, motor means for actuating said lever,

connecting means between the motor means and' lever .providing for movement of the lever` bythe driver actuated means independent of move- 1 ment of the motor means, control means for said motor means responsive to movement of said on rod 39 that thecombined distances Band C f driver Vactuated means, and connecting means trol means providing for actuationof the lever in a limited' range by vthe driver actuated means without actuation of the controlmeansl l 4. yA vehicle clutch operating devic'e comprising l* va clutch actuating lever, driver actuated means for operating'saidlever directly under force apconnected to the clutch operating leverjand si.- multaneously movable `at all times therewith,'mo tor operating means for the clutch lever controlled by the driver actuated means, and a lost` motion connection between the motor actuating means and the clutch actuating lever providing for operation ofthe clutch actuating lever by thel erating the clutch by footpressure, a common op- 4 l erating pedal positively connecting with the moplied by the driver, said means being positivelyr driver actuated means independently of the V anda lost motion movement, less ascenso pedal and lever simultaneously movable at all v times. motor operating means for the clutch lever, a lost motion connection betweenf the motor operating means and clutch lever providing for actuation of the clutch lever by the pedal independently of the motor means, control means for the motor means actuatable by the pedal andresponsive to movement of the pedal fromdifierent positions to render said motor operative and inoperative.

6.'.A vehicle clutch operating device. comprising a clutch actuating lever, a pedal, means rigidly connecting the pedaito the clutch lever for motor means. oi' the pedal independently oi.'- the control means. l

8. A vehicle clutch operating device comprising a yclutch actuatinglever, a pedal actuating :member directly connecting with the lever, a mo- .A 'tor operator connecting with the lever through l a lost motion connection' providing for movement actuation thereof directly by force exertedby the`- driver on the pedal, motor operating means for the clutch lever, a lost motion connection be-f.

. tween the motor operatingmeans and clutch lever vproviding tor actuation of the clutch lever by the pedal independently of the motor means,

control means for the motor-'means actuatable by the pedal, e lost motion connection between) the pedal and motor control 'means' providing for limited movement o! the clutch lever by the pedal independently 'of the 'motor operating means, and4 friction. means-between the pedai ly connecting the clutch lever` to the pedal forl .lever'directly by force applied"I actuation of the by the driver to the pedal, motor operating means ior-the clutch lever, control means for said motion connection between the motor means and the clutch lever providing for movement ofrthe clutch lever independently of the motor means,

cfthe motor control means.

o! the lever independently oi the motor means, motor control means connected to the lever'and actuatable by the pedal member, a. lost motion ,connecticn'providing for `limited movement of the lever 'by the pedal independentlyl oi'. the motor control' means, and va. friction connection between 'the-leverand motor control means providing for actuation of the motor control means upon movement of the pedal from any adjusted position and cperativefafter actuation of the,` motor control means to cause the pedal to move independently 9. A clutch operating device comprising a servo motor, a pedal reversely movable ina path between two spaced end positions, means rigidly connecting the pedal .andclutch, connecting y jmeans between the servo -motor and clutch in#1 "servo motor. 'control' means for the motor'ree sponsive to movement of the pedal in'one ldi- I rectionai'rom any-position'in its'path' tocause the motor te engage the clutch', a ls't'lnotion.v

-tor means ractuat'able by the pedal, a lost mo,-

connection between the motor A control means and the pedal allowing by the lost motion provided .theconnection between th'e'clufoh lever and.l i

cluding a lost motion connection providing tor v movement ofthe clutch independently o! the connection between the pedal-and control means. providing tor-limited movement. less than the complete distance'betvveen the two end partitions,7 W oi.' the pedal independently ,6i the motorcontrol f means, .thepedal being operablein eitherliirecl tion over a' limited range determined byfits lost motion eonnection'witli the'motor control means to regulate reengagementoi the'clutcla through with the clutch, 8nd

ite. rigid connection operable when moved in one direction beyond said limited range irom any position in its path to actuate the control means t0 vit theclutch.

the motor 

